Nasturtium Tropaeolum majus
Nasturtium (Tropaeolum majus) is an annual flowering plant in the Tropaeolaceae family. It grows 25–40 cm (10–16 in) tall and 40 cm–1 m (16 in–3.3 ft) wide, wants full sun and low water, and is hardy to about 2 °C (36 °F). Space plants about 40 cm (16 in) apart.
Plan Nasturtium in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Nasturtium at a glance
| Type | Annual flowering plant |
|---|---|
| Family | Tropaeolaceae |
| Mature height | 25–40 cm (10–16 in) |
| Mature spread | 40 cm–1 m (16 in–3.3 ft) |
| Spacing | 40 cm (16 in) centre to centre |
| Sun | Full sun, at least 5 h of direct sun a day |
| Water | Low; drought tolerance moderate, waterlogging tolerance none |
| Cold hardiness | About 2 °C (36 °F) once established (roughly USDA zone 10) |
| Heat stress | Likely above about 30 °C (86 °F) |
| Flowering | about 6–9 weeks after planting, for 11–17 weeks |
| Days to maturity | About 60 days from planting |
| Wind tolerance | Low |
| Pollinator value | Moderate |
| Edible | Yes: leaves, flowers |
| Common in gardens of | 🇬🇧 United Kingdom, 🇺🇸 United States, 🇵🇪 Peru, 🇫🇷 France, 🇦🇺 Australia |
Is Nasturtium toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
Nasturtium is edible and listed as non-toxic to cats and dogs.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Nasturtium
Good neighbours
- good With Brassicas (cabbage family): Nasturtiums act as a trap crop for cabbage white butterflies and blackfly, drawing some pressure away from brassicas. Evidence C
See Nasturtium in a botanical garden
It grows in these sample gardens, which you can walk through in 3D:
- UC Botanical Garden, Berkeley (8 plants)
- Monet’s gardens at Giverny (72 plants)
Questions about Nasturtium
- How far apart should I plant Nasturtium?
- About 40 cm (16 in) apart, centre to centre. A mature plant spreads 40 cm–1 m (16 in–3.3 ft).
- Does Nasturtium need full sun?
- Full sun: at least 5 hours of direct sun a day.
- How much water does Nasturtium need?
- Low water. Drought tolerance is moderate and waterlogging tolerance none.
- How cold-hardy is Nasturtium?
- It tolerates about 2 °C (36 °F) once established, roughly USDA zone 10. As an annual it is usually planted out after the last frost.
- When does Nasturtium flower?
- About 6–9 weeks after planting, for 11–17 weeks.
- Is Nasturtium poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. Nasturtium is edible and listed as non-toxic to cats and dogs.
- What grows well with Nasturtium?
- Nasturtiums act as a trap crop for cabbage white butterflies and blackfly, drawing some pressure away from brassicas.
Sources and evidence
Evidence grade C (C: plausible, mixed evidence).
- ASPCA Toxic and Non-Toxic Plant List, ASPCA
- FAO Irrigation and Drainage Paper 56 — Crop Evapotranspiration, FAO
- RHS Plant Finder, Royal Horticultural Society
- University extension gardening guides (general), Various land-grant university extensions
Notes and assumptions
- Typical garden-cultivar values; varieties differ.
- Thrives in poor soil; rich soil gives more leaf, fewer flowers.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Mashua Tropaeolum tuberosum
- Sunflower Helianthus annuus
- French marigold Tagetes patula
- English lavender Lavandula angustifolia
- Zinnia Zinnia elegans
- Cosmos Cosmos bipinnatus
- Purple coneflower Echinacea purpurea
- Foxglove Digitalis purpurea